Telescopic mast



c. THORPE TELESCOPIC MAST July 23, 1957 Filed April 7, 1953 FIG. I

INVENTOR. CHARLES L. THORPE TELESCOPIC MAST Charles L. Thorpe,Eatontown, N. J., assignor to the United States of America asrepresented by the Secretary of the Army Application April 7, 1953,Serial No. 347,420

Claims. (Cl. 18926) (Granted under Title 35, U. S. Code (1952), see.266) The invention described in the following specification and claimsmay be manufactured and used by or for the Government for governmentalpurposes, without the payment to me of any royalty thereon.

The present invention relates to a portable mast.

The invention is concerned particularly with that type of mast made upof a plurality of telescoping tubes, each of approximately the samelength. In such masts, the first tube of the mast is secured or fixedand all other tubes are movable. When collapsed or unextended, each ofthe sections are telescopically engaged within each other. By a uniquesystem of pulleys aflixed at the upper end of each section, and separatelengths of cables, the ends of which, with the exception of the firsttube, terminate at the top and bottom of alternate sections of the mast,the mast can be raised to its full length. 'This is accomplished bypulling the cable, which is secured to the base of the second section,over the top of the first section, thereby shortening the distance ofthe cable confined within the telescoping sections, causing said sectionto be raised. As said section is being raised, the third section will ofnecessity be raised, inasmuch as there is a cable extending from thebottom of the third section to the top of the first section, and as thesecond section is raised the third section will move up simultaneously.In like fashion, all the remaining tubular sections of the mast will beelevated.

Heretofore, in masts of the type described above, the cable was eithermanually pulled or wound upon a winch, usually by a hand crank. Masts soconstructed were usually installed upon a fixed base or foundation, suchas the top of a building, cast into a firm cement foundation, or mountedupon a vehicle such as a truck body. Masts so constructed do not readilylend themselves to varied usage due to the limitations exacted by themanner in which the masts are mounted and supported as indicated above.

A typical use of such masts is for supporting an antenna of a radioreceiver and/or transmitting set. It has been found, however, that whenusing masts of the type described above, the mobility or extent of useof a radio set would be limited by the travel of the truck body uponwhich such mast would be mounted. Also such masts once attached to avehicle would become a semipermanent attachment to the body and couldnot be readily removed if needed elsewhere.

It is, therefore, a primary object of the present invention to overcomethe aforesaid difficulties and disadvantages by the provision of a mastof the general type outlined above, that is portable and readilyassembled for use at any desired site.

An important feature of the present invention resides in the provisionof a portable telescopic type mast in combination with a cradle thatwill permit automatic erection of the mast at any desired location. Bythe incorporation of the cradle, there is no need of thewinch typeerection means, thereby eliminating a relatively high cost itemheretofore required for the operation of such masts.

Other objects and advantages will appear as the description proceeds tobe read in conjunction with the drawings in which:

Fig.1 is a side elevation al view of the cradle and the mast, partiallyshown, in open or extended position;

Fig. 2 is a side elevational view of the cradle closed and with the mastin collapsed position;

Fig. 3 is a view in perspective showing the first tubular section of themast and its associated travelling sleeve and fixed collar;

Fig. 4 is a diagrammatic view showing the cable and pulley arrangementof the first three sections of the mast in collapsed position, and

Fig. 5 is a sectional view of the cradle and mast in locked positiontaken on the line 5-5 of Fig. 2.

Referring to the drawing, the supporting carriage is shown generally as11. The carriage comprises, in part, a pair of spaced substantiallyparallel aligned rails 13. Each of the rails 13 is channel shaped incross-section, and of sufficient depth to accommodate a trolley as morefully described hereinafter. Positioned between the rails 13 is a casingor housing generally designated as 15. The housing 15 comprises twolongitudinally aligned U-shaped sections, the upper section beingdesignated as 17 and the lower section designated as 19 respectively.The space formed between the abutting sections 17, 19 serves as astorage area for the mast generally designated as 21 when the mast is inits collapsed position as shown in Fig. 2. The upper section 17 isprovided with a cutout 18 to permit a trolley (hereinafter described) toride freely to prevent any possible jamming. The same section 17 isfurther provided with an opening 16 which is utilized when locking thevarious components when the mast is raised as hereinafter set forth. Forlocking the sections 17, 19 there are provided a pair of latches, one oneach side of the panels as shown at 23 so that when transported thesections will not separate. The lower section 19 is further providedwith four angle irons 25, each having one of their respective sidessecured, by Welding or the like, to the sides of the lower sections 19.The other side of each angle iron extends perpendicularly outwardly fromthe section and is provided with an opening 26, through which stakes canbe driven into the ground to afford a supporting means for the cradle11. The rails 13 are held in position by a pair of bolts 24 and 27, withbolt 24 extending through the lower section 19 while bolt 27 extendsthrough a pair of cars 29 each of which is welded to the respective sidewalls of the section 19. The bolt 27 is not fixedly held in the openingsof the ears 29, but can be readily removed so that the upper section 17can be raised to its elevated position as shown in Fig. l as hereinafterdescribed. A bolt 31 extends through the first section of the mast andboth the upper and lower sections 17 and 19, about which pin the uppersection 17 and the first section of the mast pivot.

In the description of the mast that follows, for convenience ofdescription, various sections of the mast will be designated as first,second and third sections. Such designations, i. e. first, will indicatethat portion of the mast that is the bottom or lowermost section of themast when fully extended, the term second section will indicate the nextsucceeding section and so forth.

In addition, when in the specification, the terms top and bottom areused in describing parts of the sectional portions of the mast, the termtop will be meant to indicate the upper portion of any one section ofthe mast when erected, and the term bottom will indicate the lowerportion of the same section.

In the perspective view of Fig. 3, there is shown the first section at33. All the sections of the mast are tubes,

3 wherein. each succeeding. section is of smaller diameter than. thetube preceding it, so that the. tubes. can be. tel scopically engaged asshown in Fig. 4. V

Rigidly secured to and encompassing the top end of the. section 33. is.a fixed-collar: 35-. The: colder-U315 is: made up. of a. pairof1semi-circular plates 36, prouided; with extending flanges 37, andsecured together" by bolts 39. Within a cavity formed: between one; pairof flanges are a pair of non-linearly aligned reels 41,43, which are.carried on and rotate about shaft 45 which in turn are secured to theflanges 37'. Circumferentially spaced. about the outer periphery of the.plates 36., and extending therethrough, are apljurality of rollerbearings 47 to permit ease of movement between the first and-secondsections of the mast. While. not shown in; the-drawings. each; ofthe'tubular sections of, the mast are; likewise provid with bearingssimilar to those shown at 47 designated as 4.7.

Also, encompassing the. first. section 3.3 iS. a freely slidable tubularsleeve 49; which, is spaced: from first. section 33 by a plurality ofroller bearings 51- which serve to ease the movement of the sleeve; 49in its travel as hereinafter described. Attached to the surface of thesleeve 49 is a pulley 53 supported by a. shaft 55. Alsosecured to thesurface of the sleeve 49 are. a pair of trolleys. 56 spaced 180 apart.The wheels of each trolley are of a diameter slightly smaller than thatof the widthof, the rails 13 and are carried on shafts 57- whichterminate. in the base 58. In turn, the base 58. is supported by a shaft6%) which is pivotably secured to the slidable sleeve 49. By means ofthe pivotable shaft, the trolleys 56 can freely ride within the rails13.

In Fig. 4 there are shown, in; section, partial views of the first,second and third tubular: sections of the mast. The first section isshown at. 3.3, and, the, details of the fixed collar 35 and the slidablesleeve 49'- have been; de-

end of second section 59 is secured a fixed collar 73 having a singlepulley 77 positioned, therein and; rotatable on a shaft 79 which issecured to the side walls of the flange. Also shown in Fig. 4 is apartial VlQW; of the third tubular section. at 3.1 which is spaced;fromfsecond section 59 by means of roller bearings 4.7 which also assistin case of movement of the. second. and third tubular sections relativeto each other. Section 81 is. similarly provided with a pulley at itstop end (not. shown) and a bolt 85 secured to its lower end.

For coupling the various tubular sections of the. mast so that they canbe raised to their extended. position, utilizing the supporting cradleheretofore. described, the following cable looping. system is utilized.For linking the first and second sections av single length of cable 87is initially secured to the bolt 39 of the fixed collar 37.. The cablethen is brought over the pulley -3. of the movable sleeve 49 and thenbrought: over. the reel 41. From reel 41 the cable extends over thepulley 67 of the second section 59 and then back to and: over the pulley43. From pulley 43 the cable 87 is then brought back to. the. lower endof second section 59 where; it isrsecured to the bolt 71. The cablelinkage between the first section 33 and the third tubular section 81 isa single length of cable 89 which is tied to the bottom of section 81 atbolt 85 and then looped over pulley 77 in the flange of the fixed collar73 of the second section and to one of the bolts 39 in a flange of thefixed collar 35. of the first section where it is securely tied.

The succeeding sections of the mast. are linked in a manner identical tothe way in which the first and third sections are linked as describedimmediately above. Accordingly, there is shown a partial section ofcable 91 which is tied to the fixed collar of second section 59 andwhich extends over a pulley (not shown) on the top of the third section81 and is secured to the bottom of the fourth section (not shown). inthe same manner that the cable 89 is secured to the bottom of section81. All succeeding sections are linked in similar manner.

When it is desired to raise the mast to the extended position as shownin Fig. 1, the device heretofore described is operated in the followingmanner., T heentire assembly is transported to the site where the mastis to be erected and staked to the ground by driving stakes through theopenings. 26 of supports 25. The latch 23 is then opened allowing theupper sections 17 of the casing tobe raised. The locking bolt; 27 is.then temporarily removed from its openings through the rails 13 and theears 29. The upper section 17 of the. casing is then raised. to theposition. shown in Fig. 1. In this position the. opening 16 of the upperportion 17 of the casing will be in register with theopenings in therails 13 and the opening in the car 29. The bolt 27 is then reinsertedthrough all of the openings indicated above. The bolt 27 is preferablythreaded so that a nut may be screwed onto it thereby assuring that thecomponents will be securely locked. Such locking action will insure thatthe; raised section 17 willv remain rigid at all times. To elevate themast to its extended position the first tubular section 33 is grasped atits upper end and lifted upwardly. In such movement, the sliding sleeve49 carried by trolleys 55 will travel in the rails 13 of the carriagesupport. As section 33 of the mast is being raised, the slidable sleevewill move in a direction away from the fixed collar 35. In such movementthe cable 87 within the first and second sections will be shortened,thereby urging the second section upwardly.

At the same time as the second tubular section 81 is being raised andextended along with its fixed collar. 73, the length of cable 89 betweenthe second and third sections, and linking first section 33 and thirdsection 81, will be shortened thereby urging third tubular section 81upward. All other sections of the mast will be simultaneously extended.A conventional form of locking stop (not shown) is provided to lock eachsection of the mast once itreaches its fully extended position.

T o prevent the mast. from falling or tilting, there are secured to theupper section 17 of the casing, two arcuate shaped. bands 92 each ofwhich are hinged to each. side of the section, and provided, with aclasp 93. After the mast is erected, the bands are brought together andjoined by the clasp 93. thereby securing the mast.

For supporting the mast within the casing, there are provided aplurality of supporting brackets 95 and 97 respectively, with bracket 95being secured to the side walls of lower section 19 or the casing, andbracket 97 being secured to the side walls of upper section 17'.

Although there has been shown herein a detailed prefer-red form of theinvention, it is obvious that certain parts may be modified withoutdeparting from the invention. It is therefore intended that thisdisclosure .cover all such modifications as come within the scope of theappended claims.

What is claimed is: 1. In a mast comprising a plurality of telescopingtubu- .lar sections emanating from a first tubular section whereinhousing along which guide. said. slidable sleeve is directed,

the spacing between the fixed ends of said guide being substantiallyequal to the length of said first tubular section, whereby upon movementof said slidable sleeve on said first section and along said guide assaid first section is pivotally elevated at a point proximal to one ofthe terminal ends of said guide, said second section will be raised andall succeeding sections of said mast Will be urged upwardly.

2. In a mast comprising a plurality of telescoping tubular sectionsemanating from a first tubular section wherein each succeeding sectionof said mast is urged upwardly by movement of the section preceding it,a housing, a first pivotable tubular section having a sleeve traversablethereon, said sleeve including a pulley and a trolley extending from theouter surface of said sleeve, a second tubular section slidable in saidfirst section, and discrete successive sections slidable in the sectionpreceding it, a cable extending from said first section over said pulleyto said second section and discrete cables linking alternate sections ofsaid mast thereafter, a guide supported by and afiixed to said housingalong which said trolley can be directed, the spacing between the fixedends of said guide being substantially equal to the length of said firsttubular section whereby as said first tubular section is pivotablyelevated at a point proximal to one of the terminal ends of said guide,said sleeve will be longitudinally displaced causing second section tobe raised and all succeeding sections of said mast to be urged upwardly.

3. A mast of the type set forth in claim 2 wherein the guide supportedby said housing comprises a substantially channel-shaped rail.

4. In a mast comprising a plurality of telescoping tubular sectionsemanating from a first tubular section wherein each succeeding sectionof said mast is urged upwardly by movement of the section preceding it,a first pivotable tubular section having a slidable sleeve thereon, saidsleeve having a pulley mounted thereon, a second tubular sectiontelescopically slidable in said first section, a third tubular sectiontelescopically slidable in said secend section and successive sectionstelescopically slidable in the section preceding it, separate cablemeans linking said first and second sections over the pulley of saidslidable sleeve, said first and third sections and alternate sectionsthereafter, and guide means for directing said slidable sleeve, thespacing between the ends of said guide means being substantially equalto the length of said first tubular section whereby upon movement ofsaid slidable sleeve on said first section and along said guide meanssaid first section is pivotably elevated at a point proximal to one ofthe ends of said guide means and all the succeeding sections of saidmast will be urged upwardly.

5. In a mast comprising a plurality of telescoping sections emanatingfrom a first tubular section wherein each succeeding section of saidmast is urged upwardly by movement of the section preceding it, ahousing, a first pivotable tubular section having a sleeve traversablethereon, said sleeve including a first pulley and a trolley extendingfrom the outer surface of said sleeve, a pair of reels secured to saidfirst section, a second tubular section slidable in said first sectionand having a second pulley at one end thereof, and discrete successivetubular sections slidable in the section preceding it, a cable ex-'tending from said first section over said first pulley to one of saidreels and over said second pulley then to said second of said reels andthen to said second section, and discrete cables linking alternatesections of said mast thereafter, a guide supported by and aflixed atits ends to said housing along which said trolley can be directed, thespacing between the fixed ends of said guide being substantially equalto the length of said first tubular section, whereby as said firsttubular section is pivotably elevated at a point proximal to one of theends of said guide said sleeve will be longitudinally displaced causingsaid section to be raised and all succeeding sections of said mast to beurged upwardly.

References Cited in the file of this patent UNITED STATES PATENTS110,434 Clarke Dec. 27, 1870 1,132,303 Carr Mar. 16, 1915 2,369,534Cohen Feb. 13, 1945 2,384,279 Calhoun Sept. 4, 1945 2,459,280 Lange eta1. Ian. 18, 1949 2,675,211 Regoord Apr. 13, 1954 FOREIGN PATENTS625,345 France Apr. 23, 1927

